Conventional processes are known for obtaining molded articles of resins and the like by control of molding apparatuses based on pressure, and for example, a technique for obtaining particularly thin foamed body is disclosed in JP-A-8-336853. However, such conventional processes for obtaining molded articles utilize data of outside the die obtained from a sensor. Yet, no production process or production apparatus is known for obtaining foamed body, in particular, using pressure inside the die. The process disclosed in JP-A-8-336853 mentioned above also does not use data for pressure inside the die.